Method of electrically making openings of desired configuration in metal plates.



T. E. MURRAY, In.

METHOD OF ELECTRiCALLY MAKNG OPEMNGS 0E DESIRED CONFIGURATION IN METAL PLATES.

APPL |CATION FILED oer. 10. I917.

1,252,147. Patented Jan. 1,1918.

INVENTOI? 7 414 4 ORNEY one "EE'QMAS E. MUREAY METHOD 0F ELECTEZCALLY MAKING GEEIQENG'S 0E r'mT at. in. at. cilia? BEUQHLYN,

METAL Application filed Qcto'oer 10,1917.

To ail whom it may concern.

Be it known that I, Ti-IoMAs E. MURRAY, J11, a citizen of the United States, residing at Brooklyn, in the county of Kings and State of New York, have invented a certain new and useful Improvement in Methods of Electrically Making Openings of Desired Configuration in Metal Plates, of which thefollowing is a specification.

The invention is a method of electrically making an opening or desired configuration in a metal plate. 1 herein illustrate an opening having a cylindrical portion and a flared or countersunk portion, and hence suitably shaped to receive a headed rivet, whereby said plate may be secured to another plate, or to any suitable support.

In the accompanying drawings- Figure lis a vertical section showing the plate or block in which a countersunk opening is to be made, the electrodes and forming tool being shown in elevation, and said tool being in raised position. Fig. is a similar view, showing the tool in lowered position to form the countersunk opening.

Fig. 3 is a perspective-view of the plate with the countersunk hole made therein. Similar numbers of reference indicate like parts.

4 1 is any suitable support or table, having an opening 2. On said table and insulated therefrom are electrodes 3, at, preferably of.

copper or other metal of high heat conductihility. The plate 5 in which the open.-

ing of desired coi'iiiguration, here a countersunk hole, is to he made, is placed upon said electrodes so as to cover the space 6 between thern said space being directly above the opening 2 in table 1.

Specification of Letters Eeteat. Pate ete l} J? Serial Ho.

The forming tool. 7 hasits lower extremity 8 shaped to correspond to the cylindrical portion of the countersunk hole, and its id-- terrnpte'd, leaving the plate wi h a countersunk hole in it, as shown in Fig. 3.

I claim:

l. T he method of making an opening of predetermined configuration in a I metal plate, which consists in electrically heating said plate to a plastic condition. embedding therein a tool of varying cross sectional area and of configuration corresponding to the desired contiguratimi of said opening, and then withdrawing said tool.

2. The method of making countersunk hole through a metal plate, which consists in electrically heating plate to a plastic condition, embedding therein a tool of con figuration corresponding to said countersunk hole, and then Withdrawing said tool.

In testimony whereof i; have alii-xed my signature in presence of two witnesses. THOMAS f1 M fl iii Y, Ja.

. o itnessesp' Gsn'ra'onr. l or an,

MAY lvictlansr. 

